<svg xmlns="http://www.w3.org/2000/svg" width="26" height="26" fill="none" viewBox="0 0 26 26">
  <path class="rectangle" fill="#5F8CEA" fill-opacity=".9" d="M0 12.728 12.728 0l12.728 12.728-12.728 12.728L0 12.728Z"/>
</svg>
